A one-off variant of the Defiant-class, the Incursion-class was a prototype starship operated by Starfleet Intelligence for covert missions.
Although the Incursion retained the primary armament of pulse phaser cannons and photon/quantum torpedo launchers, they were intended primarily as a weapon of last resort due to the clandestine nature of the vessel's mission profile. The ship was also fitted with a prototype holographic masking system, which allowed the ship to enter hostile territory disguised as local traffic, although this was often done in conjunction with matching the energy signature of the target as closely as possible to make the deception more convincing. (ST video games: Away Team, Armada II)